M1911 pistol
The Colt M1911Semi-Automatic Pistol was the standard sidearm of the American military from 1911 to 1985. It is a semi-automatic weapon with a seven round magazine plus one in the chamber and an effective range of 50 meters. History The history of the Colt M1911 began in early 1900s, when famous designer John M. Browning began to develop semi-automatic pistols for Colt's Patent Firearms Manufacturing Company. In 1905, Browning designed two .45 cal. semi-automatic pistols in response to government interest in a higher-caliber sidearm to replace the standard--issue .38 cal. revolvers then in use (primarily the Colt M1892). The two designs were hammer and hammerless versions of the same basic design and show a clear resemblance to the M1911. In 1906-7 the U.S. military tested several semi-automatic pistols including designs from Colt, Luger, Savage, and others. These weapons were deemed unsatisfactory for military use and the competitors were asked to improve their designs in anticipation of new trials in 1910. The Colt Model 1905 remained a popular civilian pistol. However, Browning and Colt spent the next three years engineering improvements to the Model 1905. In 1911, after further extensive testing, the new pistol and its cartridge were adopted for U.S. military service as the M1911. Prior to and during World War I, more than one million of these guns were manufactured by Colt, Springfield Armoury, Remington-UMC, Burroughs, Savage, and others. The rights to manufacture Colt/Browning design were also sold to some foreign countries, such as Norway or Argentina. In 1926, the original design was improved, following US Army Ordnance Department recommendations. These changes included:ss *1. Wider front blade sight *2. Shorter hammer spur *3. Shorter trigger *4. Curved mainspring housing *5. Simplified grip panel checkering *6. Index finger reliefs behind the trigger *7. Longer grip-safety spur The improved design was adopted by the US Military as the M1911A1 pistol. Almost 2.7 million M1911 and M1911A1s were produced for military use during World War I, World War II, Korea, and Vietnam. The M1911 continued to serve with distinction until 1985 when it was officially replaced with the Beretta M9 pistol (US-made Beretta 92FS). The M1911 is still popular among special forces due to its high stopping power and accuracy. Commercial versions of the M1911 are known as Government models. In 1929, Colt introduced a Government model in its new chambering, the .38 Super Automatic, a high power version of the earlier .38 Automatic cartridge. The .38 Super has a higher muzzle velocity which produces a flatter trajectory to the target and therefore greater accuracy. The smaller cartidge allowed a larger magazine capacity (9 rounds) and sold well on the police market. The .38 Super version is still manufactured and used mostly as competition guns due to their extreme accuracy. From 1970 to 1983, Colt manufactured the Mk. IV Series 70 Government model pistol which closely resembled the M1911A1, but included an accurized barrel bushing. Since 1983, Colt has manufactured the Mk. IV Series 80 Government model, which features an internal firing pin safety. The latest Colt product, the M1991A1, also featured Series 80 slide with firing pin safety. Colt also developed compact versions of its full-size commercial guns. The so called "Commander" versions (available as Combat Commanders, Lightweight Commanders with alloy frames, etc) have shortened barrels and slides (barrel lenght 108 mm, or 4.25 inch), with the standard size frame and grip, and standard magazine capacity of 7 rounds in .45 ACP. These guns were also available in .38 Super and 9 mm Luger chamberings. In 1972, US Army adopted the M15 General Officers Model Pistol, developed by the Rock Island Arsenal, as a self-defence weapon for high level army officers. The M15 has a brass plate insert in the left grip panel, where the name of the owner should be engraved. An even more compact version, the Colt Defender, has a shorter grip that limits magazine capacity to 6 rounds of .45 ACP. The Defender has a barrel length of 76 mm length (3 inch). Commercial Colt Officers' pistols are similar to Defenders. There are numerous M1911 "clones" manufactured by companies worldwide, including Springfield Armory, Les Baer, Kimber, Wilson, STI, Para-Ordnance, and many others. Many M1911-patterned pistols are custom built for service duty, sport shooting, and self defense. Technical Overview Technically, the M1911 is a recoil operated, locked breech semi-auto pistol. It has a single action trigger with a frame-mounted safety that locks the hammer and slide. The hammer can be locked by the manual safety in the cocked position only. An additional "grip" safety is incorporated into the rear of the grip that locks the trigger when the gun is not held in the hand properly. The barrel and slide are interlocked via lugs on the upper part of the barrel, just ahead of the chamber. After firing, the barrel and slide recoil for a short distance (called short recoil operation), before the rear part of the barrel is lowered by a tilting link that separates the barrel from the slide. The slide continues back, extracting and ejecting the spent case, compressing a recoil spring located under the barrel, and cocking the hammer. The recoil spring then returns the slide and barrel to battery, chambering a new round on the way back. When the magazine is empty, the magazine follower activates the slide stop, locking the slide in the open (rear) position. The gun is fed from a single stack, seven-round magazine. The magazine release button is located on the left side of the frame, just behind the triggerguard. Recoil operation is based on the law of conservation of momentum (Newton's Third Law, commonly paraphrased as "every action has an equal but opposite reaction"). In a recoil-operated firearm such as the M1911, the momentum of the projectile traveling forward out of the barrel is balanced by an equivalent recoil force acting on the barrel/slide assembly in the rearward direction. A recoil-operated self-loading firearm depends on proper "tuning" of the projectile's momentum (its mass multiplied by its velocity) so that there is sufficient recoil force generated to perform the extraction, ejection, and chambering of the next round. Optimal operation of a standard M1911 occurs with the use of .45 ACP ammunition of 230 grains traveling at approximately 250 meters/second. Modern Gov't/1911 clones may differ, more or less, from this description: i.e, those guns may have widebody frames that can accept dual stack, high capacity magazines; frames could be made from steel, alluminium alloys or polymer; some could have Double Action or even Double Action Only triggers, ambidextrous satety switches and slide stops etc. Sources *''Brothers In Arms:Road to Hill 30 operating manual'' *Wikipedia:M1911_Colt_pistol *Modern Firearms - Colt Government category:Pistols and Revolvers